Physical quantity detecting vibration element, physical quantity sensor, electronic apparatus, and moving object

ABSTRACT

A vibration element includes a detection signal electrode provided in a detection vibrating arm, a detection signal terminal which is provided in a support portion and electrically connected to the detection signal electrode, and a detection ground terminal provided in the support portion, and the detection ground terminal is disposed between a first connection portion which is a connection portion with a beam portion of the support portion and a second connection portion which is a connection portion with a beam portion, and is provided to extend to the outside of the first connection portion, and the detection signal terminal is provided between the detection ground terminal and an end portion of the support portion.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a divisional of U.S. application Ser. No. 14/886,681filed Oct. 19, 2015, which is based on and claims priority under 35U.S.C. 119 from Japanese Patent Application No. 2014-219772 filed onOct. 28, 2014 and Japanese Patent Application No. 2014-219771 filed onOct. 28, 2014. The contents of the above applications are incorporatedherein by reference in their entirety.

BACKGROUND 1. Technical Field

The present invention relates to a physical quantity detecting vibrationelement, a physical quantity sensor, an electronic apparatus, and amoving object.

2. Related Art

As a vibration device for detecting, for example, angular velocity, avibration element having a base portion which is positioned at a centralportion, a pair of detection arms extending from the base portion toboth sides in a y-axis direction, a pair of connection arms extendingfrom the base portion to both sides in an x-axis direction, a pair ofdrive arms extending from a tip portion of the connection arm on oneside to both sides in the y-axis direction, a pair of drive armsextending from a tip portion of the connection arm on the other side toboth sides in the y-axis direction, a pair of support portions disposedto face each other in the y-axis direction with the base portioninterposed therebetween, a pair of beam portions connecting the supportportion on one side and the base portion, and a pair of beam portionsconnecting the support portion on the other side and the base portion isknown (refer to, for example, JP-A-2010-256332).

In such a vibration element, a detection signal terminal, a detectionground terminal, and a drive signal terminal are disposed at the supportportion on one side, and a detection signal terminal, a detection groundterminal, and a drive ground terminal are disposed at the supportportion on the other side. Further, the respective terminals provided inthe support portions are aligned with each other to have substantiallythe same size. Further, a detection ground electrode capable offunctioning as a shield layer which can reduce the incorporation ofnoise to the detection signal terminal or the drive signal terminal ispositioned between connection portions with the pair of beam portions ofthe support portion. For this reason, it is not possible to sufficientlywidely form the detection ground terminal, and therefore, it is notpossible to sufficiently exhibit a function even as a shield layer.

Further, in such a vibration element, the detection signal terminal andthe drive signal terminal are disposed to extend over the lower surfaceand the upper surface of the support portion. In this manner, thedetection signal terminal and the drive signal terminal are disposed toextend over the lower surface and the upper surface of the supportportion, whereby the areas of these terminals are increased. Therefore,noise is easily incorporated from the detection signal terminal and thedrive signal terminal, and thus there is a problem in that detectionaccuracy decreases.

SUMMARY

An advantage of some aspects of the invention is to provide a physicalquantity detecting vibration element, a physical quantity sensor, anelectronic apparatus, and a moving object in which it is possible toreduce a decrease in detection accuracy by reducing the incorporation ofnoise to a detection signal terminal or a drive signal terminal.

The invention can be implemented as the following forms or applicationexamples.

Application Example 1

A physical quantity detecting vibration element according to thisapplication example includes: a vibration body having a detectionvibration portion; a support portion which supports the vibration bodyand includes a first end portion and a second end portion; a beamportion which connects the vibration body and a portion between thefirst end portion and the second end portion of the support portion; adetection signal electrode provided in the detection vibration portion;a detection signal terminal which is provided on a principal surface onone side of the support portion and electrically connected to thedetection signal electrode; and a constant potential terminal which isprovided on the principal surface on one side of the support portion andelectrically connected to a constant potential, in which a portion ofthe constant potential terminal is disposed so as to be positionedfurther toward the first end portion side than a connection portion withthe beam portion of the support portion, and the detection signalterminal is disposed further toward the first end portion side than theconstant potential terminal of the support portion.

With this configuration, a vibration element is obtained in which it ispossible to reduce the incorporation of noise to the detection signalterminal, and thus it is possible to reduce a decrease in detectionaccuracy.

Application Example 2

In the physical quantity detecting vibration element according to theapplication example, it is preferable that the physical quantitydetecting vibration element further includes a detection groundelectrode provided in the detection vibration portion and the detectionground electrode and the constant potential terminal are electricallyconnected.

With this configuration, it is possible to electrically connect theconstant potential terminal to the constant potential with a simpleconfiguration.

Application Example 3

In the physical quantity detecting vibration element according to theapplication example, it is preferable that the constant potentialterminal is further disposed between the detection signal terminal andthe first end portion of the support portion.

With this configuration, it is possible to more effectively reduce theincorporation of noise to the detection signal terminal.

Application Example 4

In the physical quantity detecting vibration element according to theapplication example, it is preferable that the constant potentialterminal is further disposed at a portion overlapping the detectionsignal terminal on a principal surface on the other side of the supportportion.

With this configuration, it is possible to more effectively reduce theincorporation of noise to the detection signal terminal.

Application Example 5

In the physical quantity detecting vibration element according to theapplication example, it is preferable that the physical quantitydetecting vibration element includes a pair of the beam portions and theconstant potential terminal is disposed between a first connectionportion which is a connection portion with the beam portion on one sideof the support portion and a second connection portion which is aconnection portion with the basin portion on the other side, and isdisposed to extend further to the first end portion side than the firstconnection portion.

With this configuration, it is possible to more stably connect thevibration body to the support portion.

Application Example 6

In the physical quantity detecting vibration element according to theapplication example, it is preferable that the constant potentialterminal is further disposed to extend further to the second end portionside than the second connection portion.

With this configuration, it is possible to more widely dispose theconstant potential terminal.

Application Example 7

In the physical quantity detecting vibration element according to theapplication example, it is preferable that the vibration body includes adrive vibration portion and the physical quantity detecting vibrationelement further includes: a drive signal electrode provided in the drivevibration portion; and a drive signal terminal which is provided betweenthe constant potential terminal on the principal surface on one side ofthe support portion and the second end portion and electricallyconnected to the drive signal electrode.

With this configuration, it is possible to reduce the incorporation ofnoise from the drive signal terminal to the detection signal terminal.

Application Example 8

In the physical quantity detecting vibration element according to theapplication example, it is preferable that the constant potentialterminal is further disposed between the drive signal terminal and thesecond end portion of the support portion.

With this configuration, it is possible to more effectively reduce theincorporation of noise from the drive signal terminal to the detectionsignal terminal.

Application Example 9

In the physical quantity detecting vibration element according to theapplication example, it is preferable that the constant potentialterminal is further disposed at a portion overlapping the drive signalterminal on the principal surface on the other side of the supportportion.

With this configuration, it is possible to more effectively reduce theincorporation of noise from the drive signal terminal to the detectionsignal terminal.

Application Example 10

A physical quantity detecting vibration element according to thisapplication example includes: a vibration body having a detectionvibration portion; a support portion which supports the vibration body;a detection signal electrode provided in the detection vibrationportion; a detection signal terminal which is provided on a principalsurface on one side of the support portion and electrically connected tothe detection signal electrode; and a constant potential electrode whichis provided on a principal surface on the other side of the supportportion, is positioned so as to overlap the detection signal terminalwhen viewed in a plan view, and is electrically connected to a constantpotential.

With this configuration, a physical quantity detecting vibration elementis obtained in which it is possible to reduce a decrease in detectionaccuracy by reducing the incorporation of noise to the detection signalterminal.

Application Example 11

In the physical quantity detecting vibration element according to theapplication example, it is preferable that the physical quantitydetecting vibration element further includes: a detection groundelectrode which is provided in the detection vibration portion andelectrically separated from the detection signal electrode; and adetection ground terminal which is provided on the principal surface onone side of the support portion and electrically connected to thedetection ground electrode, and the detection ground terminal and theconstant potential electrode are electrically connected.

With this configuration, it is possible to simply electrically connectthe constant potential electrode to the constant potential.

Application Example 12

In the physical quantity detecting vibration element according to theapplication example, it is preferable that the constant potentialelectrode includes a first continuous portion which is continuouslyprovided on the principal surface on one side through a side surface ofthe support portion, and the detection signal terminal is positionedbetween the detection ground terminal and the first continuous portion.

With this configuration, it is possible to more effectively reduce theincorporation of noise to the detection signal terminal.

Application Example 13

In the physical quantity detecting vibration element according to theapplication example, it is preferable that the vibration body includes adrive vibration portion, the physical quantity detecting vibrationelement further includes: a drive signal electrode provided in the drivevibration portion; and a drive signal terminal which is provided on theprincipal surface on one side of the support portion and electricallyconnected to the drive signal electrode, and the constant potentialelectrode is positioned so as to overlap the drive signal terminal whenviewed in a plan view.

With this configuration, it is possible to reduce the incorporation ofnoise to the drive signal terminal. Further, it is possible to reduceelectrostatic coupling between the drive signal terminal and thedetection signal terminal, and thus it is possible to effectivelyreduce, for example, the incorporation of noise from the drive signalterminal to the detection signal terminal.

Application Example 14

In the physical quantity detecting vibration element according to theapplication example, it is preferable that the constant potentialelectrode includes a second continuous portion which is continuouslyprovided on the principal surface on one side through a side surface ofthe support portion and the drive signal terminal is positioned betweenthe detection ground terminal and the second continuous portion.

With this configuration, it is possible to more effectively reduce theincorporation of noise to the drive signal terminal. Further, it ispossible to reduce electrostatic coupling between the drive signalterminal and the detection signal terminal, and thus it is possible tomore effectively reduce, for example, the incorporation of noise fromthe drive signal terminal to the detection signal terminal.

Application Example 15

In the physical quantity detecting vibration element according to theapplication example, it is preferable that the detection ground terminalis positioned between the detection signal terminal and the drive signalterminal.

With this configuration, it becomes easy to dispose the first continuousportion and the second continuous portion.

Application Example 16

A physical quantity sensor according to this application exampleincludes: the physical quantity detecting vibration element according tothe application example.

With this configuration, a physical quantity sensor having highreliability is provided.

Application Example 17

An electronic apparatus according to this application example includes:the physical quantity detecting vibration element according to theapplication example.

With this configuration, the electronic apparatus having highreliability is provided.

Application Example 18

A moving object according to this application example includes: thephysical quantity detecting vibration element according to theapplication example.

With this configuration, a moving object having high reliability isprovided.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the accompanyingdrawings, wherein like numbers reference like elements.

FIG. 1 is a plan view showing a physical quantity detecting vibrationelement according to a preferred embodiment of the invention.

FIG. 2 is a plan view showing an electrode of the physical quantitydetecting vibration element shown in FIG. 1.

FIG. 3 is a plan view (a transparent view) showing the electrode of thephysical quantity detecting vibration element shown in FIG. 1.

FIG. 4 is a perspective view showing an examine of a physical quantitysensor which is provided with the physical quantity detecting vibrationelement according to the invention.

FIG. 5 is a sectional view of the physical quantity sensor shown in FIG.4.

FIG. 6 is a plan view of the physical quantity sensor shown in FIG. 4.

FIG. 7 is a plan view showing a physical quantity detecting vibrationelement of the physical quantity sensor shown in FIG. 4.

FIG. 8 is a plan view showing a physical quantity detecting vibrationelement of the physical quantity sensor shown in FIG. 4.

FIG. 9 is a sectional view showing a stress relaxation layer of thephysical quantity sensor shown in FIG. 4.

FIG. 10 is a perspective view showing the configuration of a mobile type(or a notebook type) personal computer with an electronic apparatuswhich is provided with the physical quantity detecting vibration elementaccording to the invention applied thereto.

FIG. 11 is a perspective view showing the configuration of a mobilephone (also includes a PHS) with the electronic apparatus which isprovided with the physical quantity detecting vibration elementaccording to the invention applied thereto.

FIG. 12 is a perspective view showing the configuration of a digitalstill camera with the electronic apparatus which is provided with thephysical quantity detecting vibration element according to the inventionapplied thereto.

FIG. 13 is a perspective view showing the configuration of an automobilewith a moving object which is provided with the physical quantitydetecting vibration element according to the invention applied thereto.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, a physical quantity detecting vibration element, anelectronic apparatus, and a moving object according to the inventionwill be described in detail based on an embodiment shown in theaccompanying drawings.

1. Vibration Element

First, a preferred embodiment of the physical quantity detectingvibration element according to the invention will be described.

FIG. 1 is a plan view showing a physical quantity detecting vibrationelement according to preferred embodiment of the invention. FIG. 2 is aplan view showing an electrode of the physical quantity detectingvibration element shown in FIG. 1. FIG. 3 is a plan view (a transparentview) showing the electrode of the physical quantity detecting vibrationelement shown in FIG. 1. In addition, in FIG. 1, for convenience ofdescription, illustration of the electrode is omitted. Further, in thefollowing, as shown in FIG. 1, the crystal axes of a quartz crystal willbe referred to as an x-axis (an electrical axis), a y-axis (a machineaxis), and a z-axis (an optical axis) and a direction along the x-axiswill also be referred to as an “x-axis direction”, a direction along they-axis will also be referred to as a “y-axis direction”, and a directionalong the z-axis will also be referred to as a “z-axis direction”.

A vibration element (a physical quantity detecting vibration element) 6shown in FIG. 1 is a gyro element capable of detecting angular velocity.The vibration element 6 includes a vibrator element 60 made of a quartzcrystal, and an electrode disposed at the vibrator element 60, as shownin FIG. 1. However, as a material of the vibrator element 60, it is notlimited to the quartz crystal, and it is also possible to use apiezoelectric material other than the quartz crystal, such as lithiumtantalate or lithium niobate, for example.

The vibrator element 60 has a plate shape spreading in an x-y planewhich is defined by the x-axis and the y-axis which are the crystal axesof the quartz crystal, and has a thickness in the z-axis direction.However, for example, the z-axis may be slightly shifted with respect toa thickness direction. That is, with respect to a cut angle of thequartz crystal, there is no limitation thereto as long as it is possibleto achieve an object.

Further, the vibrator element 60 includes a base portion 61, detectionvibrating arms 621 and 622 as a pair of detection vibration portionsextending from the base portion 61 to both sides in the y-axisdirection, a pair of connection arms 631 and 632 extending from the baseportion 61 to both sides in the direction, drive vibrating arms 641 and642 as a pair of drive vibration portions extending from a tip portionof the connection arm 631 to both sides in the y-axis direction, drivevibrating arms 643 and 644 as a pair of drive vibration portionsextending from a tip portion of the connection arm 632 to both sides inthe y-axis direction, a pair of support portions 651 and 652 supportingthe base portion 61, a pair of beam portions 661 and 662 connecting thesupport portion 651 and the base portion 61, and a pair of beam portions663 and 664 connecting the support portion 652 and the base portion 61.Then, a vibration body 600 is configured with the base portion 61, thedetection vibrating arms 621 and 622, the connection arms 631 and 632,and the drive vibrating arms 641 to 644.

Further, the support portion 651 is provided to extend in the x-axisdirection and is connected to the beam portion 661 passing between thedetection vibrating arm 621 and the drive vibrating arm 641, betweencentral portion and an end portion (a first end portion) 651′ on the+x-axis side, and connected to the beam portion 662 passing between thedetection vibrating arm 621 and the drive vibrating arm 643, between thecentral portion and an end portion (a second end portion) 651″ on the−x-axis side. Similarly, the support portion 652 is provided to extendin the x-axis direction and is connected to the beam portion 663 passingbetween the detection vibrating arm 622 and the drive vibrating arm 642,between a central portion and an end portion (a first end portion) 652′on the +x-axis side, and connected to the beam portion 664 passingbetween the detection vibrating arm 622 and the drive vibrating arm 644,between the central portion and an end portion (a second end portion)652″ on the −x-axis side. In this manner, by connecting the two beamportions to each of the support portions 651 and 652, it is possible tomore stably support the vibration body 600. In addition, in thefollowing, for convenience of description, a connection portion with thebeam portion 661 of the support portion 651 will be referred to as a“first connection portion 651 a”, and a connection portion with the beamportion 662 of the support portion 651 will be referred to as a “secondconnection portion 651 b”. Further, a connection portion with the beamportion 663 of the support portion 652 will also be referred to as a“first connection portion 652 a”, and a connection portion with the beamportion 664 of the support portion 652 will also be referred to as a“second connection portion 652 b”.

The vibration element 6 is fixed to an object (for example, an IC 3(described later)) at the support portions 651 and 652.

Further, grooves extending along the y-axis direction are formed in bothprincipal surfaces (the upper surface and the lower surface) of each ofthe detection vibrating arms 621 and 622, and thus each of the detectionvibrating arms 621 and 622 has a substantially H-shaped cross-sectionalshape. Further, a wide hammerhead (weight portion) is provided at a tipportion of each of the detection vibrating arms 621 and 622 and thedrive vibrating arms 641, 642, 643, and 644. However, the grooves may beomitted from the detection vibrating arms 621 and 622, and thehammerheads may be omitted from the detection vibrating arms 621 and 622and the drive vibrating arms 641, 642, 643, and 644. Further, each ofthe drive vibrating arms 641, 642, 643, and 644 may have a substantiallyH-shaped cross-sectional shape by forming grooves in both principalsurfaces thereof.

Next, the electrode disposed at the vibrator element 60 will bedescribed.

As shown in FIGS. 2 and 3, the electrode includes a detection signalelectrode 671 a, a detection signal terminal 671 b, a detection groundelectrode 672 a, a detection ground terminal (a constant potentialterminal) 672 b, a drive signal electrode 673 a, a drive signal terminal673 b, a drive ground electrode 674 a, and a drive ground terminal 674b.

Drive Signal Electrode and Drive Signal Terminal

The drive signal electrodes 673 a are disposed on the upper surface andthe lower surface (portions excluding the hammerhead) of each of thedrive vibrating arms 641 and 642 and both side surfaces of each of thedrive vibrating arms 643 and 644. The drive signal electrodes 673 a areelectrodes for exciting the drive vibration of the drive vibrating arms641 to 644.

The drive signal terminal 673 b is disposed on the lower surface of thesupport portion 652. Further, the drive signal terminal 673 b isdisposed further toward the −x-axis side than the second connectionportion 652 b of the support Portion 652, that is, between the secondconnection portion 652 b and the end portion 652″. Further, the drivesignal terminal 673 b is electrically connected to the drive signalelectrodes 673 a disposed at the drive vibrating arms 641 to 644,through drive signal wiring disposed at the beam portion 664.

Drive Ground Electrode and Drive Ground Terminal

The drive ground electrodes 674 a are disposed on the upper surface andthe lower surface (portions excluding the hammerhead) of each of thedrive vibrating arms 643 and 644 and both side surfaces of each of thedrive vibrating arms 641 and 642. The drive ground electrodes 674 a havean electric potential which becomes a constant potential (for example, areference potential such as a ground) with respect to the drive signalelectrodes 673 a.

The drive ground terminal 674 b is disposed on the lower surface of thesupport portion 651. Further, the drive ground terminal 674 b isdisposed further toward the x-axis side than the second connectionportion 651 b of the support portion 651 b, that is, between the secondconnection portion 651 b and the end portion 651″. Further, the driveground terminal 674 b is electrically connected to the drive groundelectrodes 674 a disposed at the drive vibrating arms 641 to 644,through drive ground wiring disposed at the beam portion 662.

The drive signal electrodes 673 a, the drive signal terminal 673 b, thedrive ground electrodes 674 a, and the drive ground terminal 674 b aredisposed, whereby it is possible to drive and vibrate the drivevibrating arms 641 to 644 by generating an electric field between thedrive signal electrode 673 a and the drive ground electrode 674 adisposed at each of the drive vibrating arms 641 to 644 by applying adrive signal (voltage) between the drive signal terminal 673 b and thedrive ground terminal 674 b.

Detection Signal Electrode and Detection Signal Terminal

The detection signal electrodes 671 a are disposed on the upper surfaceand the lower surface (the inner surfaces of the grooves) of each of thedetection vibrating arms 621 and 622. The detection signal electrodes673 a are electrodes for detecting an electric charge which is generatedby the detection vibration when the detection vibration of the detectionvibrating arms 621 and 622 is excited.

One detection signal terminal 671 b is disposed for each of the supportportions 651 and 652. The detection signal terminal 671 b which isdisposed at the support portion 651 is disposed on the lower surface(the principal surface on one side) of the support portion 651. Further,the detection signal terminal 671 b is disposed further toward the+x-axis side than the first connection portion 651 a of the supportportion 651, that is, between the first connection portion 651 a and theend portion 651′. Further, the detection signal terminal 671 b iselectrically connected to the detection signal electrode 671 a disposedat the detection vibrating arm 621, through detection signal wiringformed at the beam portion 661. On the other hand, the detection signalterminal 671 b which is disposed at the support portion 652 is disposedon the lower surface of the support portion 652. Further, the detectionsignal terminal 671 b is disposed further toward the +x-axis side thanthe first connection portion 652 a of the support portion 652, that is,between the first connection, portion 652 a and the end portion 652′.Further, the detection signal terminal 671 b is electrically connectedto the detection signal electrode 671 a disposed at the detectionvibrating arm 622, through detection signal wiring disposed at the beamportion 663.

Detection Ground Electrode and Detection Ground Terminal

The detection ground electrodes 672 a are disposed on both side surfacesof each of the detection vibrating arms 621 and 622. The detectionground electrodes 672 a have an electric potential which becomes aconstant potential (far example, a reference potential such as apotential which becomes a ground) with respect to the detection signalelectrodes 671 a.

The detection ground terminal 672 b is disposed at each of the supportportions 651 and 652. The detection ground terminal 672 b disposed ateach of the support portions 651 and 652 includes a first portion 672 b1 which is positioned at a central portion of the lower surface (theprincipal surface on one side) of each of the support portions 651 and652, a second portion 672 b 2 which is positioned on the end portion651′ side of the lower surface of each of the support portions 651 and652, a third portion 672 b 3 which is positioned on the end portion 651″side of the lower surface of each of the support portions 651 and 652,and a fourth portion 672 b 4 which is positioned on the upper surface(the principal surface on the other side) of each of the supportportions 651 and 652. Further, the detection ground terminal 672 b iselectrically connected to the detection ground electrode 672 a disposedat the detection vibrating arm 621, through detection ground wiringdisposed at the beam portions 661 and 662. In addition, the fourthportion 672 b 4 is disposed to extend over almost the entire area(almost the entire width) of the upper surface of each of the supportportions 651 and 652 and is connected to each of the first portion 627 b1, the second portion 672 h 2, and the third portion 672 b 3 through theside surface of each of the support portions 651 and 652. Further, thefourth portion 672 h 4 is disposed to overlap the detection signalterminal 671 b and the drive ground terminal 674 b when viewed in a planview viewed from the z-axis direction.

Further, in the following description, the fourth portion 672 b 4 whichis positioned on the upper surface (the principal surface on the otherside) of each of the support portions 651 and 652, of the detectionground terminal 672 b, will be referred to as a constant potentialelectrode 675, as distinguished from the first portion 672 b 1 which ispositioned on the lower surface (the principal surface on one side) ofeach of the support portions 651 and 652.

The first portion 672 b 1 (the detection ground terminal 672 b) isdisposed at each of the support portions 651 and 652. The first portion672 b 1 (the detection ground terminal 672 b) on one side is disposedbetween the first connection portion 651 a and the second connectionportion 651 b of the support portion 651 and on both sides thereof alongthe x-axis. More specifically, the first portion 672 b 1 (the detectionground terminal 672 b) is disposed between the first connection portion651 a and the second connection portion 651 b on the lower surface (theprincipal surface on one side) of the support portion 651, and an endportion on the +x-axis side is positioned further toward the end portion651′ side than the first connection portion 651 a and an end portion onthe −x-axis side is positioned further toward the end portion 651″ sidethan the second connection portion 651 b. That is, the first portion 672b 1 (the detection ground terminal, 672 b) is disposed to extend furtherfrom the +x-axis side than the first connection portion 651 a of thesupport portion 651 to the −x-axis side of the second connection portion651 b. The width, (the length in the x-axis direction) of the firstportion 672 b 1 (the detection ground terminal 672 b) is greater thanthe width of the detection signal terminal 671 b and the width of thedrive ground terminal 674 b. Further, the first portion 672 b 1 (thedetection ground terminal 672 b) is electrically connected to thedetection ground electrode 672 a disposed at the detection vibrating arm621, through the detection ground wiring disposed at the beam portions661 and 662.

The first portion 672 b 1 (the detection ground terminal 672 b) on theother side is disposed between the first connection portion 652 a andthe second connection portion 652 b of the support portion 652 and onboth sides thereof along the x-axis. More specifically, the firstportion 672 b 1 (the detection ground terminal 672 b) is disposedbetween the first connection portion 652 a and the second connectionportion 652 b on the lower surface (the principal surface on one side)of the support portion 652, and an end portion on the +x-axis side ispositioned further toward the end portion 652′ side than the firstconnection portion 652 a and an end portion on the −x-axis side ispositioned further toward the end portion 652″ side than the secondconnection portion 652 b. That is, the first portion 67211 (thedetection ground terminal 672 b) is disposed to extend further from the+x-axis side than the first connection portion 652 a of the supportportion 652 to the +x-axis side of the second connection portion 652 b.The width (the length in the x-axis direction) of the first portion 672b 1 (the detection ground terminal. 672 b) is greater than the width ofthe detection signal terminal 671 b and the width of the drive signalterminal 673 b. Further, the first portion 672 b 1 (the detection groundterminal 672 b) is electrically connected to the detection groundelectrode 672 a disposed at the detection vibrating arm 622, throughdetection ground wiring disposed at the beam portions 663 and 664.

As described above, the detection signal electrode 671 a, the detectionsignal terminal 671 b, the detection ground electrode 672 a, and thefirst portion 672 b 1 (the detection ground terminal 672 b) aredisposed, whereby detection vibration generated in the detectionvibrating arm 621 appears as an electric charge between the detectionsignal electrode 671 a and the detection ground electrode 672 a disposedat the detection vibrating arm 621 and can be extracted as a signal frombetween the detection signal terminal 671 b and the first portion 672 b1 (the detection ground terminal 672 b) disposed at the support portion651. Further, detection vibration generated in the detection vibratingarm 622 appears as an electric charge between the detection signalelectrode 671 a and the detection ground electrode 672 a disposed at thedetection vibrating arm 622 and can be extracted as a signal frombetween the detection signal terminal 671 b and the first portion 672 b1 (the detection ground terminal 672 b) disposed at the support portion652.

Further, the fourth portion 672 b 4 (the constant potential electrode675) is disposed on the upper surface (the principal surface on theother side) of each of the support portions 651 and 652. The fourthportion 672 b 4 (the constant potential electrode 675) disposed at thesupport portion 651 is disposed on the upper surface of the supportportion 651 and electrically connected to the detection ground terminal672 b on the support portion 651 through the side surface of the supportportion 651. On the other hand, the fourth portion 672 b 4 (the constantpotential electrode 675) disposed at the support portion 652 is disposedon the upper surface of the support portion 652 and electricallyconnected to the detection ground terminal 672 b on the support portion652 through the side surface of the support portion 652. For thisreason, the fourth portions 672 h 4 (the constant potential electrodes675) have an electric potential which becomes a ground with respect tothe detection signal electrodes 671 a, similarly to the detection groundterminals 672 b. That is, the fourth portions 672 h 4 (the constantpotential electrodes 675) are electrically connected to a constantpotential.

Further, the fourth portion. 672 b 4 (the constant potential electrode675) is disposed over almost the entire area of the upper surface ofeach of the support portions 651 and 652. For this reason, in thesupport portion 651, the fourth portion 672 b 4 (the constant potentialelectrode 675) is disposed to overlap the detection signal terminal 671b and the drive ground terminal 674 b when viewed in a plan view viewedfrom the z-axis direction, and in the support portion 652, the fourthportion 672 b 4 (the constant potential electrode 675) is disposed tooverlap the detection signal terminal 671 b and the drive signalterminal 673 b when viewed in a plan view viewed from the z-axisdirection.

Further, the fourth portion 672 b 4 (the constant potential electrode675) disposed at the support portion 651 includes the second portion (afirst wraparound portion as a first continuous portion) 672 b 2 whichwraps around to the end portion 651′ on the lower surface of the supportportion 651 via the side surface of the support portion 651, and thethird portion (a second wraparound portion as a second continuousportion) 672 b 3 which wraps around to the end portion 651″ on the lowersurface. In other words, the fourth portion 672 b 4 (the constantpotential electrode 575) disposed at the support portion 651 includesthe second portion (the first continuous portion) 672 b 2 continuouslyprovided at the end portion 651′ on the lower surface of the supportportion 651 via the side surface of the support portion 651, and thethird portion (the second continuous portion) 572 b 3 continuouslyprovided at the end portion 651″ on the lower surface. Then, thedetection signal terminal 671 b is positioned between the first portion672 b 1 (the detection ground terminal 672 b) and the second portion(the first continuous portion) 672 b 2, and the drive ground terminal674 b is positioned between the first portion 672 b 1 (the detectionground terminal 672 b) and the third portion (the second continuousportion) 672 b 3.

On the other hand, the fourth portion 672 h 4 (the constant potentialelectrode 675) disposed at the support portion 652 includes the secondportion (the first continuous portion) 672 b 2 which wraps around to theend portion 652′ on the lower surface of the support portion 652 via theside surface of the support portion 652, and the third portion (thesecond continuous portion) 672 b 3 which wraps around to the end portion652″ on the lower surface. Then, the detection signal terminal 671 b ispositioned between the second portion (the first continuous portion) 672b 2 and the first portion 672 b 1 (the detection ground terminal 672 b),and the drive signal terminal 671 b is positioned between the thirdportion (the second continuous portion) 672 h 3 and the first portion672 b 1 (the detection ground terminal 672 b).

In this manner, the second portion (the first continuous portion) 672 b2 is provided at the end portion on the +x-axis side of each of thesupport portions 651 and 652. On the other hand, the third portion (thesecond continuous portion) 672 b 3 is provided at the end portion on the−x-axis side of each of the support portions 651 and 652.

In this manner, by sandwiching the detection signal terminal 671 bbetween the second portion (the first continuous portion) 672 b 2 andthe first portion 672 b 1 (the detection ground terminal 672 b) on thelower surface of each of the support portions 651 and 652 andsandwiching the drive signal terminal 673 b between the third portion(the second continuous portion) 672 b 3 and the first portion 672 b 1(the detection ground terminal 672 b) on the lower surface of thesupport portion 652, it is possible to more effectively reduce theincorporation of noise to the detection signal terminal 671 b and thedrive signal terminal 673 b.

Further, as described above, in the support portion 651, the firstportion 672 b 1 (the detection ground terminal 672 b) is positionedbetween the detection signal terminal 671 b and the drive groundterminal 674 b, and therefore, it becomes easy to make the detectionsignal terminal 671 b be positioned between the second portion (thefirst continuous portion) 672 b 2 and the first portion 672 b 1 (thedetection ground terminal 672 b). Further, in the support portion 652,the first portion 672 b 1 (the detection ground terminal 672 b) ispositioned between the detection signal terminal 671 b and the drivesignal terminal 673 b, and therefore, it becomes easy to make thedetection signal terminal 671 b be positioned between the second portion(the first continuous portion) 672 b 2 and the detection ground terminal672 b and it becomes easy to make the drive signal terminal 673 h bepositioned between the third portion (the second continuous portion) 672b 3 and the first portion 672 b 1 (the detection ground terminal 672 b).

Further, the first portion 672 b 1 (the detection ground terminal 672 b)is disposed to extend further to the end portion 651′ side than thefirst connection portions 651 a and 652 a, and therefore, it is possibleto dispose the first portion 672 b 1 (the detection ground terminal 672b) widely and in the vicinity of the detection signal terminal 671 b.The first portion 672 b 1 (the detection ground terminal 672 b)functions as a shield layer which reduces the incorporation of noise tothe detection signal terminal 671 b, and therefore, by disposing thefirst portion 672 b 1 (the detection ground terminal 672 b) in thismanner, it is possible to reduce the incorporation of noise to thedetection signal terminal 671 b.

In particular, in this embodiment, the detection ground terminal 672 bincludes the second portion (the first continuous portion) 672 b 2 andthe detection signal terminal 671 b is sandwiched between the firstportion 672 b 1 (the detection ground terminal 672 b) and the secondportion (the first continuous portion) 672 b 2. Therefore, the shieldingeffect described above is further improved. In addition, in thisembodiment, the first portion 672 b 1 (the detection ground terminal 672b) is connected to the fourth portion 672 h 4, and therefore, thedetection signal terminal 671 b is sandwiched therebetween from thefront and the back, and thus the above-described shielding effect isfurther improved. Further, the first portion 672 b 1 (the detectionground terminal 672 b) extends further to the end portion 652″ side thanthe second connection portion 652 b, and therefore, it is possible towidely dispose the first portion 672 b 1 (the detection ground terminal672 b) and it is possible to effectively reduce the incorporation ofnoise from the drive signal terminal 673 b or the drive signal wiring tothe detection signal terminal 671 b.

In this manner, in the vibration element 6, it is possible to reduce theincorporation of noise to the detection signal terminal 671 b or thedrive signal terminal 673 b, and therefore, it is possible to reduce adecrease in angular velocity detection accuracy of the vibration element6. In other words, it is possible to improve the angular velocitydetection accuracy of the vibration element 6. In particular, asdescribed above, the fourth portion 672 b 4 (the constant potentialelectrode 675) is disposed over almost the entire area of the uppersurface of each of the support portions 651 and 652, whereby the effectthereof becomes more pronounced.

Further, the detection signal electrode 671 a, the detection signalterminal 671 b, the detection ground electrode 672 a, and the firstportion 672 b 1 (the detection ground terminal 672 b) are disposed,whereby the detection vibration generated in the detection vibrating arm621 appears as an electric charge between the detection signal electrode671 a and the detection ground electrode 672 a disposed at the detectionvibrating arm 621 and can be extracted as a signal from between thedetection signal terminal 671 b and the first portion 672 b 1 (thedetection ground terminal 672 b) disposed at the support portion 651.Further, the detection vibration generated in the detection vibratingarm 622 appears as an electric charge between the detection signalelectrode 671 a and the detection ground electrode 672 a disposed at thedetection vibrating arm 622 and can be extracted as a signal frombetween the detection signal terminal 671 b and the first portion 672 b1 (the detection ground terminal 672 b) disposed at the support portion652.

Further, in the support portions 651 and 652, the fourth portion 672 b 4(the constant potential electrode 675) is disposed so as to overlap thedetection signal terminal 671 b, whereby the fourth portion 672 b 4 (theconstant potential electrode 675) functions as a shield layer, and thusit is possible to reduce (preferably, prevent) the incorporation ofnoise to the detection signal terminal 671 b. In particular, in thesupport portion 652, the fourth portion 672 b 4 (the constant potentialelectrode 675) is disposed to overlap the drive signal terminal 673 b aswell, and therefore, it is possible to reduce the incorporation of noisefrom the drive signal terminal 673 b to the detection signal terminal671 b and it is possible to reduce the incorporation of noise to thedrive signal terminal 673 b. In this manner, by reducing theincorporation of noise to the detection signal terminal 671 b and thedrive signal terminal 673 b, it is possible to improve the angularvelocity detection accuracy of the vibration element 6. In particular,as described above, the fourth portion 672 b 4 (the constant potentialelectrode 675) is disposed over almost the entire area of the uppersurface of each of the support portions 651 and 652, whereby the effectthereof becomes more pronounced.

In addition, as the configuration of the electrode as described above,there is no particular limitation as long as it has electricalconductivity. However, for example, the electrode can be configured witha metal coating formed by stacking each coating of Ni (nickel), Au(gold), Ag (silver), Cu (copper), or the like on a metallization layer(a foundation layer) of Cr (chromium), N (tungsten) or the like.

2. Physical Quantity Sensor

FIG. 4 is a perspective view showing an example of a physical quantitysensor which is provided with the physical quantity detecting vibrationelement according to the invention. FIG. 5 is a sectional view of thephysical quantity sensor shown in FIG. 4. FIG. 6 is a plan view of thephysical quantity sensor shown in FIG. 4. FIG. 7 is a plan view showinga physical quantity detecting vibration element of the physical quantitysensor shown in FIG. 4. FIG. 8 is a plan view showing a physicalquantity detecting vibration element of the physical quantity sensorshown in FIG. 4. FIG. 9 is a sectional view showing a stress relaxationlayer of the physical quantity sensor shown in FIG. 4.

A physical quantity sensor 1 shown in FIG. 4 is a 3-axis angularvelocity sensor and can independently detect angular velocity ωx aroundan X-axis, angular velocity ωy around a Y-axis, and angular velocity ωzaround a Z-axis. The physical quantity sensor 1 includes a package 2with an accommodation space S formed on the inside thereof, the IC (asemiconductor device) 3 accommodated in the accommodation space 5, andthree vibration elements (physical quantity detecting vibrationelements) 4, 5, and 6 mounted on the IC 3 with a stress relaxation layer7 interposed therebetween.

Package

The package 2 includes a box-shaped base 21 having a concave portion 211which is open at the upper surface, a plate-shaped lid 22 which closesthe opening of the concave portion 211, and a seam ring 23 which isinterposed between the base 21 and the lid 22 and joins the base 21 andthe lid 22 to each other, as shown in FIG. 5. Then, the IC 3 and thevibration elements 4, 5, and 6 are accommodated in the accommodationspace S formed by closing the opening of the concave portion 211 by thelid 22. The atmosphere of the accommodation space S is not particularlylimited. However, it is, for example, in a vacuum state (a reducedpressure state of less than or equal to 10 Pa) In this way, viscousresistance is reduced, and thus it is possible to efficiently drive thevibration elements 4, 5, and 6.

The base 21 has a substantially square shape when viewed in a plan view.Further, the concave portion 211 includes a first concave portion 211 awhich is open at the upper surface of the base 21, and a second concaveportion 211 b which is open at a central portion excluding an edgeportion of the bottom surface of the first concave portion 211 a.Further, a plurality of cutout portions 212 extending from the uppersurface to the lower surface are formed in each side surface of the base21. The base 21 can be formed by sintering a stack of a plurality ofceramic green sheets of, for example, aluminum oxide, aluminum nitride,silicon carbide, mullite, glass ceramic, or the like.

Wiring 24 is disposed at the base 21. The wiring 24 includes a pluralityof internal terminals 241 disposed on the bottom surface of the firstconcave portion 211 a and electrically connected to the IC 3 through abonding wire BW, and a plurality of external terminals 242 disposed onthe bottom surface of the base 21 and respectively electricallyconnected to the corresponding internal terminal 241. Further, thewiring includes internal wiring 243 formed in the base 21, or acastellation electrode 244 formed in the cutout portion 212, and eachinternal terminal 241 and the external terminal 242 correspondingthereto are electrically connected through the internal wiring 243 andthe castellation electrode 244. Such wiring can be configured with, forexample, tungsten (W), molybdenum (Mo), manganese (Mn), or the like, andwith respect to portions (for example, the internal terminal 241, theexternal terminal 242, and the castellation electrode 244) exposed fromthe base 21, a plated metal layer of gold (Au) or the like may be formedon the surface thereof.

The lid 22 has a plate shape and is joined to the upper surface of thebase 21 with the seam ring 23 interposed therebetween. As a constituentmaterial of the lid 22, there is no particular limitation. However, itis preferable to use an alloy such as Kovar, for example. In addition,the lid 22 may be electrically connected to a ground wiring included inthe wiring 24, through the seam ring 23, for example. In this way, it ispossible to make the lid 22 function as a shield portion which blocksnoise from the outside of the package 2.

IC

The IC 3 is fixed to the bottom surface of the second concave portion211 b by silver paste or the like. Further, the IC 3 has a substantiallyrectangular shape when viewed in a plan view, and the outer shape whenviewed in a plan view has a pair of outer edges (sides) 31 and 32extending in the Y-axis direction, and a pair of outer edges (sides) 33and 34 extending in the X-axis direction, as shown in FIG. 6.

The IC 3 includes, for example, an interface unit 3 i which performscommunication with an external host device, a drive/detection circuit 3y which drives the vibration element 4 and detects the angular velocitymy applied to the vibration element 4, a drive/detection circuit 3 xwhich drives the vibration element 5 and detects the angular velocity ωxapplied to the vibration element 5, and a drive/detection circuit 3 zwhich drives the vibration element 6 and detects the angular velocity ωzapplied to the vibration element 6. Further, a plurality of connection39 are disposed on the upper surface of the IC 3, and the connectionterminals 39 and the internal terminals 241 are connected through thebonding wires BW. In this way, the IC 3 can perform communication withthe host device through the external terminals 242. In addition, as acommunication method of the IC 3, there is no particular limitation, andit is possible to use, for example, SPI (registered trademark) (SerialPeripheral Interface), or I²C (registered trademark) (Inter-IntegratedCircuit). In particular, in the physical quantity sensor 1 of thisembodiment, it is made so as to be able to select the communicationmethod between SPI and I²C.

Here, the plurality of connection terminals 39 are disposed to bedivided at three areas: a first terminal disposition area SS1, a secondterminal disposition area SS2, and a third terminal disposition areaSS3, set on the upper surface of the IC 3, as shown in FIG. 6. The firstterminal disposition area SS1 is disposed along the outer edge 33 to bebiased to the outer edge 31 side, the second terminal disposition areaSS2 is disposed along the outer edge 34 to be biased to the outer edge31 side, and the third terminal disposition area SS3 is disposed alongthe outer edge 32 to be biased to the outer edge 34 side.

In the first terminal disposition area SS1, for example, digital signalterminals such as a digital signal terminal for a slave select signal SSfor selecting the communication method, a digital signal terminal for adata input: signal MOSI, a digital signal terminal for a clock signalSCLK, and a digital signal terminal for a data output signal MISO aredisposed together. In each of the second terminal disposition area SS2and the third terminal disposition area SS3, for example, analog signalterminals such as a ground terminal for ground GND, a power-supplysignal terminal for a power supply VDDI of the interface unit 3 i, apower-supply signal terminal for a power supply VDD of thedrive/detection circuits 3 x, 3 y, and 3 z, and a test signal terminalfor a test are disposed together.

In this manner, the digital signal terminals and the analog signalterminals are disposed to be divided at the different areas, whereby itis possible to reduce the incorporation of a digital signal to theanalog signal terminals (wiring). For this reason, the physical quantitysensor 1 in which it is possible to reduce noise and it is possible toperform more accurate driving is provided. In particular, in thisembodiment, the first terminal disposition area SS1 is disposed as faraway from the second and third terminal disposition areas SS2 and SS3 aspossible, and therefore, it is possible to more effectively exhibit theabove-described effect.

Vibration Elements

Vibration Element 4

The vibration element 4 is a vibration element which is a so-called“H-type” and can detect the angular velocity ωy around the Y-axis. Thevibration element 4 includes a vibrator element 40 made of quartzcrystal, and an electrode (not shown) disposed at the vibrator element40, as shown in FIG. 7. However, as a material of the vibrator element40, it is not limited to the quartz crystal, and it is also possible touse a piezoelectric material such as lithium tantalate or niobate, forexample.

The vibrator element 40 has a plate shape spreading in the x-y planewhich is defined by the x-axis and the y-axis which are the crystal axesof the quartz crystal, and has a thickness in the z-axis direction.Further, the vibrator element 40 includes a base portion 41, a pair ofdrive vibrating arms 421 and 422 extending side by side from the baseportion 41 to the −y-axis side, a pair of detection vibrating arms 431and 432 extending side by side from the base portion 41 to the +y-axisside, a pair of adjustment vibrating arms 441 and 442 which extends fromthe base portion 41 to the +y-axis side and is positioned on both sidesof the detection vibrating arms 431 and 432, a support portion 45supporting the base portion 41, and a connection portion 46 connectingthe base portion 41 and the support portion 45.

The vibration element 4 is fixed to the stress relaxation layer 7 at thesupport portion 45. Further, the fixing of the vibration element 4 tothe stress relaxation layer 7 is performed by using a fixing member 8having electrical conductivity, and the vibration element 4 and the IC 3are electrically connected through the fixing member 8 and the stressrelaxation layer 7. As the fixing member 8, it is not particularlylimited, and for example, a metal brazing material, a metal bump, anelectrically-conductive adhesive, or the like can be used.

Further, the support portion 45 has an approximately “U” shape and isdisposed so as to surround the pair of drive vibrating arms 421 and 422.Further, the connection portion 46 includes a beam portion 461connecting an end portion on the −x-axis side of the base portion 41 andan end portion on the −x-axis side of the support portion 45, a beamportion 462 connecting an end portion on the +x-axis side of the baseportion 41 and an end portion on the +x-axis side of the support portion45, and a beam portion 463 connecting end portions on both sides in thex-axis direction of the base portion 41 and a central portion of thesupport portion 45. In particular, in this embodiment, each of the beamportions 461 and 462 has a shape extending in the +y-axis direction fromthe base portion 41 and folded back in the −y-axis direction, and thebeam portion 463 has a shape having a curved portion 463 a curved so asto meander in the middle thereof. In this way, it is possible tosufficiently soften the connection portion 46, and thus it is possibleto reduce the occurrence of unnecessary vibration (in particular,vibration in a y-axis translation mode).

An excitation electrode (not shown) is provided in each of the drivevibrating arms 421 and 422, and a drive mode indicated by an arrow A isexcited by applying an oscillation drive signal (alternating voltage)from the IC 3 (the drive/detection circuit 3 y) to the excitationelectrodes. Then, when the drive vibrating arms 421 and 422 arevibrating in the drive mode, if angular velocity co around a detectionaxis J₄ is applied, a detection mode indicated by an arrow B is excited.A detection electrode (not shown) is provided in each of the detectionvibrating arms 431 and 432, and detection signals (electric charge s)which are generated by the vibration of the detection vibrating arms 431and 432 are extracted from the detection electrodes. Then, the IC 3 (thedrive/detection circuit 3 y) detects the angular velocity ω based on theextracted detection signals.

Vibration Element 5

The vibration element 5 is a vibration element which is a so-called“H-type”, and can detect the angular velocity ωx around the X-axis. Thevibration element 5 has the same configuration as the vibration element4 described above, and therefore, the description thereof is omitted.

Vibration Element 6

The vibration element 6 can detect the angular velocity (ωz around theZ-axis. The vibration element 6 has the same configuration as that inthe embodiment described above.

The vibration element 6 is fixed to the stress relaxation layer 7 at thesupport portions 651 and 652. Further, the fixing of the vibrationelement 6 to the stress relaxation layer 7 is performed by using thefixing member 8 having electrical conductivity, and the vibrationelement 6 (the respective terminals 671 b to 674 h) and the IC 3 areelectrically connected through the fixing member 8 and the stressrelaxation layer 7.

A drive signal is applied from the IC 3 (the drive/detection circuit 3)to the drive signal electrode 673 a, whereby a drive mode as indicatedby an arrow C is excited, as shown in FIG. 8. Then, when the drivevibrating arms 641 to 644 are vibrating in the drive mode, if angularvelocity ω around a detection axis J₆ is applied, a detection mode asindicated by art arrow D is excited. Then, detection signals (electriccharges) which are generated by the vibration of the detection vibratingarms 621 and 622 are extracted from the detection signal electrodes 671a. Then, the IC 3 (the drive/detection circuit 3 z) detects the angularvelocity ω based on the extracted detection signals.

The configurations of the vibration elements 4, 5, and 6 have beendescribed above. Next, the disposition of the vibration elements 4, 5,and 6 on the IC 3 will be described.

First, the disposition of the vibration element 4 will be described. Thevibration element 4 is disposed such that the detection axis J₄coincides with the Y-axis, as shown in FIG. 6. In this way, it ispossible to detect the angular velocity coy by the vibration element 4.Further, the vibration element 4 is disposed at a position biased to theouter edge 32 side and the outer edge 34 side of the upper surface ofthe IC 3. Further, the third terminal disposition area SS3 is positionedon the +X axis side of the vibration element 4 (between the vibrationelement 4 and the outer edge 32), and the second terminal dispositionarea SS2 is positioned on the −X-axis side of the vibration element 4(between the vibration element 4 and the outer edge 31). Further, thevibration element 4 is disposed with the adjustment vibrating arms 441and 442 protruding from the outer edge 34 of the IC 3 to the +Y-axisside when viewed in a plan view. That is, the vibration element 4 isdisposed such that the adjustment vibrating arms 441 and 442 do notoverlap the IC 3 when viewed in a plan view.

Next, the disposition of the vibration element 5 will be described. Thevibration element 5 is disposed such that a detection axis J₅ coincideswith the X-axis, as shown in FIG. 6. In this way, it is possible todetect the angular velocity ωx by the vibration element 5. Further, thevibration element 5 is disposed at a position biased to the outer edge32 side and the outer edge 33 side of the upper surface of the IC 3. Forthis reason, the vibration element 5 is positioned on the −Y-axis sidewith respect to the vibration element 4 (between the vibration element 4and the outer edge 33). Further, the first terminal disposition area 531is positioned on the −X-axis side of the vibration element 5 (betweenthe vibration element 5 and the outer edge 31). Further, the vibrationelement 5 is disposed with adjustment vibrating arms 541 and 542protruding from the outer edge 32 of the IC 3 to the +X-axis side whenviewed in a plan view.

Next, the disposition of the vibration element 6 will be described. Thevibration element 6 is disposed such that the detection axis J₆coincides with the Z-axis, as shown in FIG. 6. In this way, it ispossible to detect the angular velocity ωz by the vibration element 6.Further, the vibration element 6 is disposed at a position biased to theouter edge 31 side of the upper surface of the IC 3. For this reason,the vibration element 6 is positioned on the −X-axis side with respectto the vibration elements 4 and 5 (between the vibration elements 4 and5 and the outer edge 31). Further, the first terminal disposition areaSS1 is positioned on the −Y-axis side of the vibration element 6(between the vibration element 6 and the outer edge 33) and the secondterminal disposition area 352 is positioned on the +Y-axis side (betweenthe vibration element 6 and the outer edge 34).

Here, as described in the above-described embodiment, the detectionground terminal 672 b (the constant potential electrode 675) is widelydisposed on the upper surface of each of the support portions 651 and652 of the vibration element 6, and the detection ground terminal 672 b(the constant potential electrode 675) functions as a shield layer whichreduces the incorporation of noise to the detection signal terminal 671b or the drive signal terminal 673 b. For this reason, the incorporationof the digital signal from the digital terminal (wiring) disposed in thefirst terminal disposition area SS1 to the detection signal terminal 671b and the drive signal terminal 673 b, or the incorporation of theanalog signal from the analog terminal (wiring) disposed in the secondterminal disposition area SS2 to the detection signal terminal 671 b andthe drive signal terminal 673 b is reduced.

Further, the vibration element 6 is disposed to be biased further to thesecond terminal disposition area SS2 side than the first terminaldisposition area SS1. In other words, the vibration element 6 isdisposed such that a distance D_(SS2) between itself and the secondterminal disposition area SS2 is shorter than a distance D_(SS1) betweenitself and the first terminal disposition area SS1. In this way, thevibration element 6 can be separated from the first terminal dispositionarea SS1 as much as possible, and thus the incorporation of the digitalsignal to the vibration element 6 is reduced. For this reason, it ispossible to reduce the incorporation of noise to the drive signal or thedetection signal, and thus the physical quantity sensor 1 in which it ispossible to perform more accurate driving is provided.

Further, the vibration element 6 is disposed such that an arrangementdirection of the support portions 651 and 652 coincides with the Y-axisdirection. In the vibration element 6, the length thereof in thearrangement direction of the support portions 651 and 652 is longer thanthe length thereof in a direction orthogonal thereto (an extendingdirection of the connection arms 631 and 632), and therefore, due tosuch disposition, it is possible to effectively a space on the uppersurface of the IC 3. For this reason, for example, it is possible toshorten the distance between the outer edge 31 and the outer edge 32, inother words, it is possible to shorten the lengths of the outer edge 33and the outer edge 34, and thus it is possible to attain a reduction inthe size of the IC 3.

As described above, the vibration elements 4 and 5 are disposed side byside in the Y-axis direction at the area on the outer edge 32 side ofthe upper surface of the IC 3 and the vibration element 6 is disposed atthe area on the outer edge 31 side of the upper surface of the IC 3,whereby it is possible to dispose these three vibration elements 4, 5,and 6 in a relatively small space. For this reason, it is possible toattain a reduction in the size of the IC 3, and accordingly, it ispossible to attain a reduction in the size of the physical quantitysensor 1.

In addition, the physical quantity sensor of this embodiment includesthe three vibration elements 4, 5, and 6. However, as the number ofvibration elements, it is not particularly limited as long as itincludes the vibration element 6, and the vibration elements 4 and 5 maybe omitted, and another vibration element or an acceleration detectionelement may be added.

Stress Relaxation Layer

The stress relaxation layer 7 is provided on the upper surface of the IC3, as shown in FIGS. 4 and 6. Further, the stress relaxation layer 7includes a first stress relaxation layer 71 which is provided betweenthe IC 3 and the vibration element 4 and in which the vibration element4 is mounted on the upper surface thereof, second stress relaxationlayer 72 which is provided between the IC 3 and the vibration element 5and in which the vibration element 5 is mounted on the upper surfacethereof, and a third stress relaxation layer 73 which is providedbetween the IC 3 and the vibration element 6 and in which the vibrationelement 6 is mounted on the upper surface thereof.

The first, second, and third stress relaxation layers 71, 72, and 73 areprovided, whereby an impact that the package receives is relaxed, andthus it becomes difficult for the impact to be transmitted to thevibration elements 4, 5, and 6. Further, stress which is generated dueto the difference in thermal expansion between the IC 3 and thevibration elements 4, 5, and 6 is relaxed, and thus the vibrationelements 4, 5, and 6 are not easily deformed (bent). For this reason, byproviding the first, second, and third stress relaxation layers 71, 72,and 73, it is possible to increase the mechanical strength of thephysical quantity sensor 1 and it is possible to more accurately detectthe angular velocity ωx, ωy, and ωz.

The first, second, and third stress relaxation layers 71, 72, and 73have the same configuration as each other, and therefore, in thefollowing, the first stress relaxation layer 71 will be described as arepresentative, and with respect to the second and third stressrelaxation layers 72 and 73, the description thereof is omitted.

The first stress relaxation layer 71 includes, for example, aninsulating film 711 stacked on the upper surface fa passivation film 38)of the IC 3, a wiring layer 712 formed on the insulating film 711 andelectrically connected to the IC 3, an insulating film 713 formed on thewiring layer 712 and the insulating film 711, and a wiring layer 714formed on the insulating film 713 and electrically connected to thewiring layer 712, as shown in FIG. 9. Then, the vibration element 4 isfixed to a terminal 714′ provided in the wiring layer 714 through thefixing member 8. In this way, the IC 3 and the vibration element 4 areelectrically connected through the wiring layers 712 and 714. In thismanner, the wiring layers 712 and 714 function as wiring (rearrangementwiring) for electrically connecting the IC 3 and the vibration element4. For this reason, a terminal 37 for being electrically connected tothe vibration element 4, of the IC 3, can be freely disposed withoutconsidering the configuration (in particular, the position of aterminal) of the vibration element 4.

Each of the insulating films 711 and 712 is configured with a resinmaterial having elasticity. As the resin material, it is notparticularly limited. However, it is possible to use polyimide,silicone-modified polyimide resin, epoxy resin, silicone-modified epoxyresin, acrylic resin, phenol resin, silicone resin, modified polyimideresin, benzocyclohutene, polybenzoxazole, or the like.

In addition, in this embodiment, the stress relaxation layer 7 isdivided into the first, second, and third stress relaxation layers 71,72, and 73. However, the first, second, and third stress relaxationlayers 71, 72, and 73 may be integrally formed. Further, the stressrelaxation layer 7 may be omitted.

3. Electronic Apparatus

Subsequently, an electronic apparatus with the vibration element 6applied thereto will be described in detail based on FIGS. 10 to 12.

FIG. 10 is perspective view showing the configuration of a mobile type(or a notebook type) personal computer with the electronic apparatuswhich is provided with the physical quantity detecting vibration elementaccording to the invention applied thereto.

In this drawing, a personal computer 1100 is configured to include amain body section 1104 provided with a keyboard 1102, and a display unit1106 provided with a display section 1108, and the display unit 1106 issupported so as to be able to rotate with respect to the main bodysection 1104 through a hinge structure section. The physical quantitysensor 1 (the vibration element 6) functioning as a angular velocitydetection unit (a gyro sensor) is built into the personal computer 1100.For this reason, the personal computer 1100 can exhibit high reliabilitywith higher performance.

FIG. 11 is a perspective view showing the configuration of a mobilephone (also includes a PHS) with the electronic apparatus which isprovided with the physical quantity detecting vibration elementaccording to the invention applied thereto.

In this drawing, a mobile phone 1200 is provided with a plurality ofoperation buttons 1202, an ear piece 1204, and a mouthpiece 1206, and adisplay section 1208 is disposed between the operation buttons 1202 andthe ear piece 1204. The physical quantity sensor 1 (the vibrationelement 6) functioning as the angular velocity detection unit is builtinto the mobile phone 1200. For this reason, the mobile phone 1200 canexhibit high reliability with higher performance.

FIG. 12 is a perspective view showing the configuration of a digitalstill camera with the electronic apparatus which is provided with thephysical quantity detecting vibration element according to the inventionapplied thereto. In addition, in this drawing, connection with externalequipment is also shown in a simplified manner.

A digital still camera 1300 produces an imaging signal (an image signal)by performing photoelectric conversion of an optical image of aphotographic subject through an imaging element such as a charge coupleddevice (CCD). A configuration is made in which a display section 1310 isprovided on the back surface of a case (a body) 1302 in the digitalstill camera 1300 and display is performed based on the imaging signalby the CCD, and the display section 1310 functions as a finder whichdisplays the photographic subject as an electronic image. Further, alight receiving unit 1304 which includes an optical lens (an imagingoptical system), the CCD, or the like is provided on the front side (theback side in the drawing) of the case 1302. If a photographer confirms aphotographic subject image displayed on the display section 1310 andthen presses a shutter button 1306, the imaging signal of the CCD atthat point in time is transmitted to and stored in a memory 1308.

Further, in the digital still camera 1300, a video signal outputterminal 1312 and an input-output terminal for data communication 1314are provided on the side surface of the case 1302. Then, as shown in thedrawing, as necessary, a television monitor 1430 is connected to thevideo signal output terminal 1312 and a personal computer 1440 isconnected to the input-output terminal for data communication 1314. Inaddition, a configuration is made in which the imaging signal stored inthe memory 1308 is output to the television monitor 1430 or the personalcomputer 1440 by a predetermined operation.

The physical quantity sensor 1 (the vibration element 6) functioning asthe angular velocity detection unit is built into the digital stillcamera 1300. For this reason, the digital still camera 1300 can exhibithigh reliability with higher performance.

In addition, the electronic apparatus which is provided with thephysical quantity sensor according to the invention can be applied to,in addition to the personal computer (the mobile type personal computer)of FIG. 10, the mobile phone of FIG. 11, and the digital still camera ofFIG. 12, for example, an ink jet type discharge apparatus (for example,an ink jet printer), a laptop type personal computer, a television, avideo camera, a video tape recorder, a car navigation device, a pager,an electronic notebook (also including an electronic notebook with acommunication function), an electronic dictionary, a desktop electroniccalculator, electronic game equipment, a word processor, a workstation,a video phone, a security television monitor, electronic binoculars, aPOS terminal, medical equipment (for example, an electronic thermometer,a sphygmomanometer, a blood glucose meter, an electrocardiogrammeasuring device, an ultrasonic diagnostic device, or an electronicendoscope) a fish finder, various measuring instruments, meters andgauges (for example, meters and gauges of a vehicle, an aircraft, or aship), a flight simulator, or the like.

4. Moving Object

Subsequently, a moving object which is provided with the physicalquantity detecting vibration element according to the invention will bedescribed in detail based on FIG. 13.

FIG. 13 is a perspective view showing the configuration of an automobilewith the moving object which is provided with the physical quantitydetecting vibration element according to the invention applied thereto.

The physical quantity sensor 1 (the vibration element 6) functioning asthe angular velocity detection unit is built into an automobile 1500,and it is possible to detect the attitude of a car body 1501 by thephysical quantity sensor 1. A detection signal of the physical quantitysensor 1 is supplied to a car body attitude control device 1502, and thecar body attitude control device 1502 detects the attitude of the carbody 1501 based on the signal and can control the hardness and softnessof a suspension or control a brake of an individual wheel 1503 accordingto a detection result. In addition, such attitude control can beutilized in a bipedal walking robot or a radio-controlled helicopter. Asdescribed above, the physical quantity sensor 1 is incorporated forrealization of the attitude control of various moving objects.

The physical quantity detecting vibration element, the physical quantitysensor, the electronic apparatus, and the moving object according to theinvention have been described above based on the embodiments shown inthe drawings. However, the invention is not limited thereto and theconfiguration of each section can be replaced with any configurationhaving the same function. Further, any other configuration may be addedto the invention. Further, the invention may include a combination oftwo or more of optional configurations (characteristics) of therespective embodiments described above.

Further, in the embodiment described above, a configuration has beendescribed in which the detection ground terminal 672 b includes thefirst portion 672 b 1 to the fourth portion 672 b 4. However, the secondportion 672 b 2 to the fourth portion 672 b 4 may be omitted.

Further, in the embodiment described above, the detection groundterminal 672 b configuring the fourth portion 672 b 4 (the constantpotential electrode 675) is electrically connected to the detectionground electrode 672 a. However, as the fourth portion 672 b 4 (theconstant potential electrode 675), it may not be electrically connectedto the detection ground electrode 672 a as long as it is connected to aconstant potential. Further, the fourth portion 672 b 4 (the constantpotential electrode 675) is not limited to a ground as long as it hasconstant potential.

The entire disclosure of Japanese Patent Application Nos: 2014-219771,filed Oct. 28, 2014 and 2014-219772, filed Oct. 28, 2014 are expresslyincorporated by reference herein.

What is claimed is:
 1. A physical quantity detecting vibration elementcomprising: a vibration body having a detection vibration portion; asupport portion which supports the vibration body; a detection signalelectrode provided in the detection vibration portion; a detectionsignal terminal which is provided on a first principal surface on oneside of the support portion and electrically connected to the detectionsignal electrode; and a constant potential electrode which is providedon a second principal surface on another side of the support portionthat faces in a direction opposite from a direction in which the oneside faces, the constant potential electrode being positioned so as tooverlap the detection signal terminal when viewed in a plan view, andbeing electrically connected to a constant potential.
 2. The physicalquantity detecting vibration element according to claim 1, furthercomprising a detection ground electrode which is provided in thedetection vibration portion and electrically separated from thedetection signal electrode; and a detection ground terminal which isprovided on the first principal surface on the one side of the supportportion and electrically connected to the detection ground electrode,wherein the detection ground terminal and the constant potentialelectrode are electrically connected.
 3. The physical quantity detectingvibration element according to claim 2, wherein the constant potentialelectrode includes a first continuous portion which is continuouslyprovided on the first principal surface on the one side through a sidesurface of the support portion, and the detection signal terminal ispositioned between the detection ground terminal and the firstcontinuous portion.
 4. The physical quantity detecting vibration elementaccording to claim 2, wherein the vibration body includes a drivevibration portion, the physical quantity detecting vibration elementfurther comprises a drive signal electrode provided in the drivevibration portion, and a drive signal terminal which is provided on thefirst principal surface on the one side of the support portion andelectrically connected to the drive signal electrode, and the constantpotential electrode is positioned so as to overlap the drive signalterminal when viewed in a plan view.
 5. The physical quantity detectingvibration element according to claim 4, wherein the constant potentialelectrode includes a second continuous portion which is continuouslyprovided on the first principal surface on the one side through a sidesurface of the support portion, and the drive signal terminal ispositioned between the detection ground terminal and the secondcontinuous portion.
 6. The physical quantity detecting vibration elementaccording to claim 5, wherein the detection ground terminal ispositioned between the detection signal terminal and the drive signalterminal.
 7. A physical quantity sensor comprising: the physicalquantity detecting vibration element according to claim
 1. 8. Anelectronic apparatus comprising: the physical quantity detectingvibration element according to claim 1.